1. Field of the Invention
This invention relates to field of amusement devices, particularly teeter-totters. Specifically, the invention relates to a spring balanced single rider teeter-totter.
2. Background
Teeter-totters, also known as seesaws, have long been popular items of playground equipment for children. Teeter-totters come in various configurations, but most are fundamentally similar. In the most basic configuration, a teeter-totter can be simply a plank supported near its center for pivotal movement.
A variation of the conventional two-rider teeter-totter is one adapted for use by a single rider. One-sided, single-rider teeter-totters typically consist of a pivoting seat with a counterbalance, such as a spring, to balance the rider's weight. The rider rides up and down on the seat in a bouncing manner against the elastic resistance of the spring or other counterbalance device. An early version of a single rider teeter-totter is shown in U.S. Pat. No. 1,586,254. This device has a board with a seat at one end and a pivot near the opposite end. A spring is attached at the extreme opposite end of the board to balance the rider's weight. The height of the pivot and, indirectly, the counterbalancing effect of the spring is adjusted by raising or lowering a pair of threaded boards that support the pivot. This is a cumbersome adjustment and weakens the structural integrity of the frame. Furthermore, there is no direct adjustment for the resistance of the spring, nor is there any safety cover for the spring.
Other prior art single rider teeter-totters, including, for example, the device shown in U.S. Pat. No. 3,968,962, disclose adjustments for the spring resistance, that require that the spring or springs be repositioned. The adjustment process requires that the seat be lifted to release any tension and that the spring then be disconnected and reattached at a different location. In some of the prior art devices, the spring or springs must be moved from one detent to another, or the point of attachment of the spring must be slid along a track. These prior art methods of adjusting the spring tension are both cumbersome and dangerous. If the springs become detached or dislocated during use of the teeter-totter, the counterbalancing force may be reduced or eliminated altogether causing the rider to strike the ground forcibly and unexpectedly. Furthermore, fingers can be easily pinched while manually adjusting the springs.